NPC Demand System
The NPC demand engine is the core of Tradorn's economy. Every 45 seconds, it runs through a series of calculations to determine who buys what, from which shop, and at what volume. Here is how it works under the hood.
Step 1: Population Distribution
The total NPC population (10,000 + 500 per active player) is split across regions by their population share. For example, with 20 active players:
- Total NPCs: 10,000 + (500 x 20) = 20,000
- North Harbor (14%): 2,800 NPCs
- Central Plaza (18%): 3,600 NPCs
- Riverside (3%): 600 NPCs
Step 2: Category Consumption
Each NPC consumes products based on category rates:
| Category | Rate per NPC per Hour | Per Cycle (45s) |
|---|---|---|
| Food | 0.15 | ~0.001875 |
| Clothing | 0.06 | ~0.000750 |
| Technology | 0.03 | ~0.000375 |
| Luxury | 0.01 | ~0.000125 |
Multiply the regional NPC count by the per-cycle rate to get the raw demand for each category in each region. In North Harbor with 2,800 NPCs, food demand per cycle is roughly 5.25 units.
Step 3: Price Elasticity
NPCs are price-sensitive. The demand engine applies a price elasticity factor:
- At or below base price: Full demand — NPCs buy eagerly
- 10-30% above base: Slight demand reduction — most NPCs still buy
- 30-60% above base: Noticeable demand drop — only some NPCs are willing to pay
- 60%+ above base: Severe demand penalty — very few NPCs purchase
The key takeaway: moderate markups are sustainable, but extreme pricing kills demand. Find the sweet spot where margin and volume multiply to maximum revenue.
Step 4: Appeal Scoring
When multiple shops compete for the same demand, the engine calculates an appeal score for each shop based on:
- Price competitiveness — Lower relative price increases appeal
- Product quality tier — Premium > Standard > Cheap in appeal
- Shop reputation — Higher reputation means NPCs trust and prefer your shop
The demand is then distributed among competing shops in proportion to their appeal scores. A shop with twice the appeal of its competitor gets roughly twice the customers.
Step 5: Market Coverage Caps
After appeal-based distribution, the engine enforces caps:
- No single shop captures more than 40% of category demand in a region
- No single player captures more than 85% total
Excess demand spills over to other shops or goes unfulfilled if no alternatives exist.
Practical Implications
- Monopolies are impossible — the 40% cap ensures competition always matters
- Quality matters — Premium products give a genuine mechanical advantage in appeal scoring
- Reputation compounds — Established shops consistently outperform new ones at identical prices
- Region choice matters — A shop in a high-population region with modest appeal can outsell a shop with perfect appeal in a low-population region